Joint implants are well known in the art. For example, one of the most common types of joint prosthetic devices is a knee implant including a femoral component and a tibial component. Other common joint implants are associated with, for example, the hip and shoulder.
The shape and size of various joint implants are becoming increasingly more complex and may include, for example, one or more concavities and/or convexities, as described in above-mentioned U.S. application Ser. No. 10/997,407. Traditional implant manufacturing processes, which may even include manual steps, and which may be satisfactory for less complex shaping, are becoming inadequate.
Furthermore, joint implants, such as a knee implant that includes tibial and femoral components, often require a relatively large cut on, for example, the tibia. This is due, in part, to the needed thickness (for strength and/or reliability) of the polyurethane tibial component. The cut on the tibia, upon which the tibial component rests, provides space for the needed thickness of the polyurethane tibial component, without overstuffing the joint. Such cuts are highly invasive, resulting in loss of bone stock, and over time, osteolysis frequently leads to loosening of the prosthesis. Further, the area where the implant and the bone mate degrades over time, requiring that the prosthesis be replaced. Since the patient's bone stock is limited, the number of possible replacement surgeries is also limited for joint arthroplasty.